HOUSTON — Rain pelted this battered city anew Monday as emergency teams — aided by a growing contingent of citizen-rescuers — plunged into waist-deep water seeking people stranded by devastating, historic flooding in the wake of Hurricane Harvey.

Officials in Texas said Monday afternoon that at least nine people appear to have died as a result of the storm battering the state. That toll includes six people in Harris County, home to Houston; one person in Rockport, near where Harvey made landfall; and another person in La Marque, near Galveston.

Authorities expect the toll to rise as rescue efforts continue and more rain, rising rivers and surging floodwaters pummel the Gulf Coast. Forecasters say up to 20 inches of additional rain could fall on parts of Texas and Louisiana by Thursday.

About 2,000 people had been brought to safety with more still in need of help. Yet even with several deaths attributed to the storm, the full toll of Harvey’s destruction remained unclear in Houston and across Texas and Louisiana, with officials warning that the flooding would linger and saying more than 30,000 people would be forced from their homes.

“We are not out of the woods yet,” Elaine Duke, the acting Homeland Security secretary, said during a Monday morning briefing in Washington. “Harvey is still a dangerous and historic storm.”

The latest confirmed fatality Monday came at around noon in Porter, a town immediately north of Houston in Montgomery County. Police said a woman in her 60s was napping in her bedroom when a large oak tree landed on top of her mobile home. By the time rescue workers waded through the waist-deep water to rescue the woman, she was dead.

“This is the most significant flooding that we’ve ever seen,” said Montgomery County Sheriff’s Captain Bryan Carlisle, who added that deputies had performed at least 60 rescue missions on Monday. “It’s helped that the rain has slowed down somewhat. We’re going to be dealing with flooding for the foreseeable future.”

Fears also grew beyond Texas, where the floodwater pounding this city and others was measured in feet, not inches. President Trump on Monday declared “emergency conditions” in Louisiana, where forecasts have called for as much as two feet of rainfall in some areas.

During a news conference Monday, Trump said he expects Congress to take “very rapid action” to help the storm-ravaged areas. Trump, who is visiting Texas on Tuesday, also told reporters he may return to Texas on Saturday and, depending on the storm’s movements, could also visit Louisiana the same day.

“I look very much forward to it,” Trump said of his planned Tuesday trip to Texas. “Things are being handled really well. The spirit is incredible, of the people.”

Louisiana Gov. John Bel Edwards (D) had asked Trump for an emergency disaster declaration, similar to one signed for Texas last week, saying that Harvey posed a “serious danger to life and property” in the state, which is just a year removed from a massive flood disaster. A flash flood watch was issued Monday morning for part of Louisiana as well as part of Mississippi.

The immediate focus for many remained Houston, the country’s fourth-largest city and a sprawling metropolitan area, which faced dire circumstances and National Weather Service forecasts warning of more heavy rainfall.

Two reservoirs were opened to release water to relieve the stress the downpour has caused in the region, which has seen as much rain in a few days as it averages in an entire year.

“We are seeing catastrophic flooding, and this will likely expand and it will likely persist as it’s slow to recede,” Louis W. Uccellini, the NWS director, said at the Monday morning briefing.

Parts of Harris County, which encompasses Houston, were pelted with 30 inches of rain in the past 72 hours, the Weather Service reported early Monday.

Texas Gov. Greg Abbott (R) said authorities in his state are focusing on “saving lives” as Harvey continues to pound Texas on Aug. 27. (Bastien Inzaurralde/The Washington Post)

The Weather Service said Harvey’s rain is causing “catastrophic and life-threatening flooding over large portions of southeastern Texas,” and it warned of more agony to come. In an alert Monday, the service said Harvey could produce between 10 and 20 inches of additional rain along the upper Texas coast and part of Louisiana, along with as much as 50 inches of overall rainfall in some parts of Texas.

“We have not seen an event like this,” William “Brock” Long, administrator of the Federal Emergency Management Agency, said Monday morning at a news briefing. “You could not draw this forecast up. You could not dream this forecast up.”

Updated look at rainfall thus far with many 72-h rainfall totals greater than 30″ and a widespread area with radar estimated totals over 25″ pic.twitter.com/YhQhqWV1xW

The National Hurricane Center said Monday that Harvey is expected to gradually shift on Tuesday before its center moves “just offshore of the middle and upper coasts of Texas through Tuesday night.” Harvey could make a second landfall northeast of Houston in Texas on Wednesday, but forecasters say that will not necessarily lead to a repeat of the damaging rain that pummeled the city.

Authorities in Texas fielded scores of calls for help throughout the night from people stranded by water, although many areas had imposed curfew overnight Sunday in hopes of cutting down on the number in need of being rescued from vehicles. Help was pouring in from swift-water rescue teams from around the country.

The Houston police dispatched officers on boats that were sent through streets where the floodwater reached the pumps at gas stations. While urging residents to stay off the roads, police have asked people with high-water vehicles and boats to assist in rescue efforts.

In Houston, the fire department responded to more 4,000 water-related calls for service. Police rescued 2,000 people in the city, and another 185 critical rescue requests were still pending, Art Acevedo, the Houston police chief, said at a news briefing Monday.

“The goal is rescue,” Houston Mayor Sylvester Turner said at the briefing. “That’s the major focus for the day.”

Acevedo also disputed social media claims suggesting that looting had erupted in the city, saying that police had arrested four people for attempting to loot.

Across Houston and suburbs many miles away, families scrambled to get out of fast-flooding homes. Rescuers, in many cases neighbors rescuing one another, used fishing boats, huge dump trucks and front-end loaders to battled driving rains.

In downtown Houston, some of the floodwater had receded. The swollen Brays Bayou had gone down several feet overnight, while some streets that had been flooded were dry as the sun rose over Houston.

Abandoned cars were left in intersections and alongside roads, and in one case, a school bus had been parked on a high grassy area and left behind. A brief respite overnight had given way to people wandering the streets in the morning, looking at the scattered debris. A woman wearing hospital scrubs, knee-high rubber boots and a backpack, carrying an umbrella, trekked through the water toward a hospital.

But by midmorning Monday, a hard rain had begun to fall again.

Austin city officials said they had been asked to shelter thousands of evacuees and were figuring out how many people they could take. A shelter at the M.O. Campbell Center in North Houston had begun turning people away Sunday evening, leaving hundreds stranded, according to local emergency officials.

All day, local fire departments, the Army Reserves and good Samaritans had brought people from their flooded homes to a fire station before transporting them to the M.O. Campbell shelter. But when it reached capacity, the shelter’s doors were shut, and at least 300 people were stranded at the fire station.

The firefighters put a call out for help, asking if anyone could take the evacuees in. One local youth pastor answered the call. The rescue teams picked up Pastor David McDougle, 26, and his wife from their flooded home so they could open the First Baptist Church North Houston as a makeshift shelter for those stranded.

McDougle said he got a call Sunday evening asking if he would let evacuees sleep at the church, so he and his wife took all the food and water they had gotten and brought it to the church.

Though they now have a roof over their heads, the church is not a designated shelter and has no food or water for the evacuees. The church reached capacity with nearly 300 people laying on the floor of the gym, and the food supply ran out around 5 a.m. People are nervous to drink tap water. The restrooms at the church will not flush, creating a mess of the place.

“It’s frustrating, but I’m just relying on God to fulfill his promises to us,” McDougle said. “We’re all praying.”

The Brazos River, which runs southwest of Houston, is expected to reach record heights in the coming days. National Weather Service models showed the river rising to 59 feet by Tuesday, topping the previous record of 54.7 feet.

Early Monday morning, the Fort Bend Office of Emergency Management issued voluntary and mandatory evacuation orders for wide areas along dozens of miles of Brazos River banks. River banks are expected to overflow across that part of the state as trillions of gallons of rainfall runoff consolidates over coming days.

“A 59-foot river level threatens to over top many of the levees in out area,” said Fort County Judge Robert Hebert. “It exceeds the design specifications of our levees.”

Herbert said anyone who ignores mandatory evacuation orders — issued for an area that includes a part of Houston with sprawling mansions — will not be aided by first responders when the waters rise.

Gov. Greg Abbott (R) on Monday activated the entire Texas National Guard in response to the storm, pushing the total deployment to 12,000, his office said.

“Our main priority is to make sure all Texans have food and water and basic services, and we will be setting up distribution points in every county where Texans can get food and water,” Abbott said at a news conference.

On Monday, the Pentagon said that active duty units were heading to staging areas in anticipation of a formal request for help, saying national guard units from across the country had readied cargo jets, Black Hawk helicopters and others to help with the response. In addition, a Pentagon search and rescue team was deploying to Fort Worth, Tex., to help, according to spokesman U.S. Army Col. Robert Manning. The Federal Emergency Management Agency said federal agencies have more than 5,000 employees working in Texas.

The devastation that evoked Hurricane Katrina in New Orleans was also reverberating around the world from the Houston area’s large international community. In India, foreign minister Sushma Swaraj posted a tweet Monday saying 200 Indian students were “marooned.”

Officials said Houston, a major center for the nation’s energy industry, had suffered billions of dollars in damage and would take years to fully recover. Oil and gas companies have shut down about a quarter of their production in the Gulf of Mexico. Spot prices for gasoline are expected to jump on Monday, but the full extent of damage will not be clear for days, companies and experts said.

The Federal Aviation Administration said Monday that Houston’s two key airports — among the busiest nationwide — would remain closed through Wednesday, which will likely cause delays and rerouting of planes across the country.

Harvey’s sheer size also became apparent Sunday as heavy rains and flooding were reported as far away as Austin and even Dallas. What started with a direct impact on the tiny coastal town of Rockport on Friday night turned into a weather disaster affecting thousands of square miles and millions of people — with no clear end in sight.

The Texas National Guard has deployed across the state, including engineers in Corpus Christi and an infantry search-and-rescue team in Rockport. Another search-and-rescue unit was staging in San Antonio and was likely to be deployed to affected areas shortly, officials said.

As the extent of the disaster became sharper, some criticized Houston officials for not calling for an evacuation of the city.

Turner had defended the decision not to evacuate, noting that it would be a “nightmare” to empty out the population of his city and the county all at once.

Texas State Rep. Armando Walle, who represents a district that stretches from northern reaches of Houston into unincorporated parts of Harris County surrounding George H.W. Bush Intercontinental Airport, on Monday defended the decision not to evacuate Houton.

“You would have had a calamity of biblical proportions,” Walle said. “That’s not an overstatement. If you put 1 million cars on the road when every major road in this region is under water, it would have been a disaster.

“There are challenges in any disaster,” Walle added, “but that decision not to call for mandatory evacuations was the right decision. I believe that you would have had thousands of people perish.”

At a news conference on Monday, Aug. 28, Federal Emergency Management Agency administrator Brock Long defended the city’s decision not to evacuate its residents ahead of Harvey’s catastrophic flooding. (The Washington Post)

Both of Houston’s major airports were closed, and many tourists and visitors found themselves stranded in hotels with no hope of leaving anytime soon. While Houston was spared Harvey’s initial onslaught, disaster suddenly beset the city, as severe storms Saturday evening gave way to flooding Sunday morning.

Though officials asked residents not to travel during the storm, in some cases, people could not wait. Early Monday morning, a man came running into the lobby of the Marriott Courtyard hotel in Southwest Houston. He said he had a pregnant woman in his truck who was about to deliver.

Crystal Manker, the hotel’s operations manager, was shocked enough that anyone made it to the hotel, which had been surrounded by deep, impassable floodwaters and abandoned, submerged cars since the night before. Nobody had gotten in or out for 24 hours. But hotel staff went with the man through the swamped parking lot, and finally into waist-deep water where his truck had stalled, with a pregnant woman and her husband inside.

The man said he had seen the husband’s desperate call on Twitter that his wife was in labor and they couldn’t get out of their home. It was close by, so he and a friend drove through the deep water and picked them up. They started toward Texas Children’s Hospital, but as they got closer to the overflowed Brays Bayou, the water became too deep to pass.

As their truck started stalling, saw the Courtyard, which is on the banks of the Bray, and ran inside to get help. Manker said she called 911, and got through after ten minutes. She told the operator the woman’s contractions were eight minutes apart, and the operator told her to call back when they got closer.

At that point Manker said the baby seemed destined to be born in a hurricane-marooned Marriott, so she and her staff rolled a bed into a ground-floor meeting room. They hurried in with sheets, towels, water, pillows and scissors.

Manker remembered that three nurses from Louisiana had been relocated to the hotel. She called them and they rushed down — even though none of them had ever delivered a baby.

As the mother-to-be lay in the bed in the meeting room for more than an hour, Manker called 911 again and told the operator contractions were down to two minutes apart. The nurses were getting ready.

Then a huge city dump truck appeared. Several men helped the woman into the truck, which then headed off into the 4-foot deep water, across the swamped bridge across the bayou and toward the hospital.

Maker was still waiting for word Monday morning on how everything went. She was most amazed at the men who answered the Twitter call for help.

“They had to be her angel,” she said.

Employees of Houston’s KHOU 11 News station had to evacuate their newsroom on Aug. 27 due to flooding as Harvey continued to pound Southeast Texas. (Stephanie Kuzydym)